CD8A and neoplasm: Response to therapy has been correlated to critical molecular and immunologic features, such as tumor mutational load (9, 10, 13, 23, 24), human leukocyte antigens (HLA) genotype (25, 26), immune infiltration into the tumor microenvironment (27), CD8+ T-cell activation (10, 28), and expression of immune checkpoint molecules such as PD-L1 (28–30).